Sierra 2500 4WD V8-6.0L (2008)
1. Obtain a new SS 2 (1), SS 3 (4), TCC PCS (7), or modulated main pressure solenoid. Install O-rings (2 and 3) and lubricate with clean
transmission fluid. Push the new solenoid into the control valve assembly (5) with the wiring harness connector in the correct position.
2. Install the solenoid retainer (6). Connect the internal wiring harness to the solenoids replaced.
3. For a new TCC PCS (7), install O-rings and lubricate with clean transmission fluid. Push the new TCC PCS (7) into the control valve assembly
with the wiring harness connector in the correct position.
4. Install the TCC PCS retainer and bolt.
Tighten the bolt to 12 N.m (108 lb in).
5. For a new SS 1 (5), install O-rings (3 and 4) and lubricate with clean transmission fluid. Push the new SS 1 (5) into the control valve assembly
with the wiring harness connector in the correct position. Install the solenoid retainer (2).
6. Install the oil pan and transmission internal oil filter. Refer to Oil Pan Replacement (See: Automatic Transmission/Transaxle/Fluid Pan/Service
and Repair/Allison - Automatic Transmission) .
Important: The FastLearn, adapt, procedure must be performed. This can be done in 1 step using a scan tool. If this procedure is not
done, the TCM adaptive values will be at the settings that it learned for the old components and will be in slow adaptive mode. Under
these conditions, it will take an unacceptably long time for the adaptive values to converge to levels suitable for the new transmission.
7. Perform the FastLearn procedure. Refer to FastLearn Procedure (See: Automatic Transmission/Transaxle/Testing and Inspection/Component
Tests and General Diagnostics/Allison - Automatic Transmission/FastLearn Procedure) .
